Effect of baffles on the flow and hydraulic efficiency of settling tanks by 2D numerical model

Subject Areas : Marine Biology

M. H.  Najafi Enferadi ¹ (Dept. of Fisheries, Islamic Azad University, Bandar Abbas Branch)
M.  Mahdavi ² (Dept. of Fisheries, Faculty of Marine Science and Technology, Islamic Azad University, Tehran North Branch)
E.  Rahimzade Asbfroushan ³ (Dept. of Fisheries, Islamic Azad University, Bandar Abbas Branch)

Received: 2015-05-17 Accepted : 2016-06-04 Published : 2016-09-21

Keywords: settling basin, Baffle, 2d model, hydraulic efficiency,

Abstract :

In this research the effect of baffle on hydraulic efficiency of settling basin was investigated by applying two-dimensional numerical model. In these experiments, a steady state for water flow is assumed and for simulating the flow disturbances and also for examining the turbulence sphere, the standard (k-ε) model is used. The present study assessed the baffle effects with regard to the submergence depth and its distance from inlet flow. In order to explore the depth of submergence two depths (25 & 50 percent of basin depth) and for its optimal location, two positions (14 & 36 percent of inlet installment) were defined. The results indicated that the depth of submergence and baffles location in the basin can have a determining influence on the efficiency and the operation of settling basin. These results also showed that when the baffle is used correctly, the inlet jet available in the basin is restrained effectively. However, by exploiting in a wrong direction it can have reverse effect and make the condition even worst. The results also showed that by using 25% basin depth submergence and a distance of 14 % of installation entrance, entrance flow jet was very well suppressed and the flow became calm and had a more uniform distribution.